Wavy coulters are presently used ahead of no-till implements--such as a planter--to fracture a narrow band of soil to prepare the soil to receive the no-till implement. The coulters are set at a sort penetrating depth of about four inches, and the amplitude of the wave from crest-to-valley is about one to two inches and generally defines the width of the band. These traditional wavy coulters are designed for only one speed, and if they go faster they throw great amounts of dirt.
The crests and valleys on presently available wavy coulters are positioned to extend out from the center of the coulter in a line generally coincident with the radius of the coulter. As each wave enters the soil, the line of the wave enters the soil at an angle with respect to vertical. Each wave, therefore, tends to compact the soil and occasionally throw lumps of the compacted soil to the rear and out of the narrow band, thus, leaving strips where no fractured soil is left in the band.
Those concerned with these and other problems recognize the need for an improved wavy coulter.